Hello Bird Nerd,
I'm up early this morning getting ready for a scouting trip and I saw this question. There are several important factors to consider about planting and as we found out over the last few seasons, it isn't just about the weather.
Last season we had one or two who waited very late until the seeds were sprouting in the Spring and they still had successful plantings. If you are very far North, I'm sure frozen ground could limit your planting activity. Snow on the ground would be a big problem as well. The biggest problem for many growers seemed to be how the seed were stored prior to planting. If you are going to be holding the seed for sometime after you receive them I really caution you on placing them in a cold refrigerator. This can cause delayed dormancy and they may not germinate properly the next Spring. Just keeping them in a cool place until you are ready to plant might be the wisest thing to do. A small amount of moisture might also help. Those of us who live south of West Virginia can plant almost all season and not be affected too much by colder weather. If you live North of there it might be a problem once the ground starts freezing. There will be others with some comments and they can steer you right. Good luck.
Hugh
